Yes you’re not the first one to raise that point. I did it for myself as a development experiment. Honestly it doesn’t matter much whether you know what the ranks mean. But there’s only five to remember, so that could be taught in tutorial form or as part of an in game encyclopedia, for curious players. Wachoffizier means watch officer. The life aboard the boat was divided in 4 hour watches, and each watch was led by an officer, who kind of ran the daily routine for his watch. I. Wachoffizier can be translated as 1st Officer. The closest in the U.S navy would be the XO, or Executive Officer, second in command after the Captain. You’ll start a campaign by picking a Captain. Then the dBU (the body of the German navy running U-boats) will assign you a boat and 4 officers: a 1st Officer, an Engineer, or Chief (LI in German), a radio operator (Funkmaat), and a Navigator (Bootsmann).